Most explainers heavily criticize and belittle Ephraim here.1 They say that Ephraim was looking for a slice of the glory; they want to be war heroes, and so their complaint is an indication of their jealousy and wounded sense of self-importance.
2 But is that what is happening? It does not appear so, when one considers this passage in light of the overall picture of Ephraim in Judges. The first reference to Ephraim in the main body of Judges is Judges 3:27–29. That’s where Ehud, a Benjaminite, calls the people of Israel to gather in the hill country of Ephraim to fight the Moabites. This shows that early on in that period, there was inter-tribal cooperation in wars against foreign enemies. This unity is celebrated in the song of Deborah in Judges 5:1–31; that song prizes unity in Israel’s warfare, and it condemns the tribes that do not partake in the war (Judges 5:14–17). The tribe of Ephraim is listed among the tribes praised for joining Barak in his campaign against Canaan.
With Gideon versus the Midianites, however, the Ephraimites are called up not at the start of the battle but at its end, to help cut off the Midianites who fled for the Jordan (Judges 7:24). Therefore, the Ephraimites complained to Gideon about not calling them up at the start, and they accused him fiercely
(Judges 8:1). Now with Jephthah, Ephraim is not called up at all. What we therefore see with Gideon and Jephthah is a failure to follow the pattern of inter-tribal cooperation set by Ehud and praised by Deborah. Ehud called out Ephraim; Gideon only called them out at the end; and Jephthah did not call at all. And so Ephraim’s complaint for not being called out to join in the war is legitimate; they see a failure in Gideon, now in Jephthah, to unite the people of Israel in the war effort. There is this crumbling relationship between the people and their leaders, as part of the downward spiral in the book.
That said, there may be a degree of wounded pride in Ephraim’s complaint. More literally, they say, “Why did you cross over to fight against the Ammonites and us you did not call to go with you?” The placement of the direct object us
before the verb suggests emphasis, and therefore the possibility of a wounded sense of self-importance. Nevertheless, this does not completely undermine their complaint.
1 The men of Ephraim were called to arms, and they crossed to Zaphon and said to Jephthah, “Why did you cross over to fight against the Ammonites and did not call us to go with you? We will burn your house over you with fire.”